Orthognathic surgery continues to evolve but still relies on a careful aesthetic analysis on which depends the surgical indications. This will be demonstrated with the example of four cases: an isolated maxillary surgery, a mandibular surgery associated with an harmonization by chin-surgery, two simultaneous maxillamandibular osteotomies (a Class II asymmetric and an important Class III). KEYWORDS -Orthognathic surgery / Maxillary osteotomy / Mandibular osteotomy / Simultaneous repositioning of maxilla, mandible and chin